Justin Mates joined the County Executive’s Office in 2019. His responsibilities include coordinating with the County’s community services departments to provide municipal services to residents across the county. Justin also helps oversee interdepartmental efforts such as the Farmworker Housing Compliance Task Force and the Safe Trailer Parks Program. During the COVID-19 pandemic, Justin served in the Emergency Operations Center and helped lead a number of response efforts, including the County’s community testing and vaccination programs.

Justin has worked for the County for over a decade. Before joining the County Executive’s Office, he served as a deputy in the County Attorney's Office, where he represented the County in areas such as affordable housing, real estate, bonds and public finance, and general litigation. In 2018, he served as the County’s real property manager overseeing all transactions and strategy for the County’s real estate portfolio. Prior to joining the County, he worked for an international development nonprofit and as an attorney in private practice.

Justin received his bachelor’s degree in political science from Stanford University with distinction and honors and his J.D. magna cum laude from Harvard Law School. He lives in San Mateo County with his wife and three children.

Department Assignments

Agriculture, Weights & Measures; Community Affairs; First 5; Human Resources; Information Services Department; LAFCo; Libraries; Parks; Planning & Building; Public Works; Real Property; Sustainability; Well Being Officer

Deputy County Executive Justin Mates
Justin Mates
Deputy County Executive